Add workaround for numpy on Windows for python 3.9

Author: AlexanderWells-diamond

setup.py

@@ -105,6 +105,9 @@ def install_for_development(self):
         # Dependency version declared in pyproject.toml
         epicscorelibs.version.abi_requires(),
         "pvxslibs>=1.3.2a2",
+        # Numpy PR #27235 was never backported to 2.0.*, so just fall back
+        # to numpy 1.*
+        "numpy<2.0 ; sys_platform == 'win32' and python_version == '3.9'",
         "numpy",
         "epicsdbbuilder>=1.4",
         "pyyaml>=6.0"